Data from: Paternal care: direct and indirect genetic effects of fathers on offspring performance

Knowledge of how genetic effects arising from parental care influence the evolution of offspring traits comes almost exclusively from studies of maternal care. However, males provide care in some taxa, and often this care differs from females in quality or quantity. If variation in paternal care is genetically based then, like maternal care and maternal effects, paternal effects may have important consequences for the evolution of offspring traits via indirect genetic effects (IGEs). IGEs and direct-indirect genetic covariances associated with parental care can contribute substantially to total heritability and influence predictions about how traits respond to selection. It is unknown, however, if the magnitude and sign of parental effects arising from fathers are the same as those arising from mothers. We used a reciprocal cross-fostering experiment to quantify environmental and genetic effects of paternal care on offspring performance in the burying beetle, Nicrophorus vespilloides. We found that IGEs were substantial and direct-indirect genetic covariances negative. Combined, these patterns led to low total heritabilities for offspring performance traits. Thus, under paternal care, offspring performance traits are unlikely to evolve in response to selection and, variation in these traits will be maintained in the population despite potentially strong selection on these traits. These patterns are similar to those generated by maternal care, indicating that the genetic effects of care on offspring performance are independent of the caregiver’s sex.我们对亲本抚育产生的遗传效应如何影响后代性状演化的认知，几乎全部源自针对母本抚育的研究。然而若干类群中的雄性也会提供抚育，且其抚育的质量或数量往往与雌性存在差异。若父本抚育的变异具有遗传基础，那么与母本抚育及母本效应类似，父本效应也可能通过间接遗传效应（indirect genetic effects, IGEs）对后代性状的演化产生重要影响。与亲本抚育相关的间接遗传效应以及直接-间接遗传协方差，可显著贡献于总遗传力，并影响关于性状如何响应选择的预测。不过目前尚不清楚父本产生的亲本效应的强度与方向，是否与母本一致。我们采用互交换亲实验（reciprocal cross-fostering experiment），量化了父本抚育对埋葬甲（Nicrophorus vespilloides）后代表现的环境效应与遗传效应。结果发现间接遗传效应较为显著，且直接-间接遗传协方差为负值。二者共同作用导致后代表现性状的总遗传力较低。因此在父本抚育的情境下，后代表现性状不太可能因选择而发生演化；即便这些性状面临潜在的强烈选择压力，种群中仍会维持这类性状的变异。上述模式与母本抚育所产生的模式相似，表明抚育行为对后代表现的遗传效应，并不依赖于抚育者的性别。